It is known that hydroxy acids have a potential for the formation of polyesters. For instance, poly(meta-oxybenzoyl) can be derived from m-hydroxybenzoic acid [Gilkey and Caldwell, J. Appl. Polym. Sci. 2, 198 (1959)]; and a polyester derived from p-(2-hydroxyethyl)benzoic acid (no methyl side groups) has been reported (Cook, et al., Brit. Pat. No. 604,985, ICI). It appeared therefore conceivable that p-(1,1-dimethyl-2-hydroxyethyl)benzoic acid may also form a polyester. However, we found that the polyester that indeed formed has completely unexpected thermal properties, advantageous for practical purposes, namely melting point (T.sub.m) allowing facile processing on conventional fiber and film melt extrusion equipment, combined with a comparatively high glass transition temperature (T.sub.g), high enough to allow uses in which retention of strength at temperatures above 100.degree. C. is important.